Light-emitting element
A light-emitting element includes a first reflection layer, a second reflection layer, a multi-layer light-emitting structure, and a light-transmitting semiconductor layer. The first reflection layer has a first reflectance, and the second reflection layer has a second reflectance greater than the first reflectance. The multi-layer light-emitting structure is between the first reflection layer and the second reflection layer. The light-transmitting semiconductor layer is located on the first reflection layer and has an upper light-extracting surface, and the first reflection layer is closer to the upper light-extracting surface than the second reflection layer. An interval between the upper light-extracting surface and the first reflection layer is equal to or smaller than 5 μm.
1. A light-emitting element, comprising:
a first reflection layer having a first reflectance;
a second reflection layer having a second reflectance greater than the first reflectance;
a multi-layer light-emitting structure disposed between the first reflection layer and the second reflection layer; and
a light-transmitting semiconductor layer disposed on the first reflection layer and having an upper light-extracting surface, wherein the first reflection layer is closer to the upper light-extracting surface than the second reflection layer, and wherein an interval between the upper light-extracting surface and the first reflection layer is equal to or smaller than 5 μm.
2. The light-emitting element of claim 1 , wherein an interval between the first and second reflection layers is equal to or smaller than 3 μm.
3. The light-emitting element of claim 1 , wherein a ratio of a maximum vertical length of the multi-layer light-emitting structure to an interval between the first and second reflection layers is equal to or greater than 0.9, and the ratio is smaller than 1.
4. The light-emitting element of claim 1 , wherein the second reflectance is greater than 95%, and the first reflectance ranges from 45% to 95%.
5. The light-emitting element of claim 1 , wherein the second reflection layer comprises a Bragg reflector.
6. The light-emitting element of claim 5 , wherein the first reflection layer comprises another Bragg reflector containing semiconductor material.
7. The light-emitting element of claim 1 , wherein the second reflection layer comprises a metal reflection mirror.
8. The light-emitting element of claim 7 , wherein the first reflection layer comprises a Bragg reflector containing semiconductor material.
9. The light-emitting element of claim 1 , further comprising a first conductive pad and a second conductive pad, wherein the multi-layer light-emitting structure comprises an n-type semiconductor layer, a p-type semiconductor layer, and an active layer disposed between the n-type semiconductor layer and the p-type semiconductor layer, and the first conductive pad is electrically connected to the n-type semiconductor layer, the second conductive pad is electrically connected to the p-type semiconductor layer, wherein the first conductive pad, the second conductive pad, and the second reflection layer are disposed on a same side of the first reflection layer.
10. The light-emitting element of claim 1 , wherein the upper light-extracting surface comprises a corrugated surface.
11. The light-emitting element of claim 1 , wherein the light-transmitting semiconductor layer has a same material as the multi-layer light-emitting structure.
12. A light-emitting element, comprising:
a first reflection layer having a first reflectance;
a second reflection layer having a second reflectance greater than the first reflectance;
a multi-layer light-emitting structure disposed between the first reflection layer and the second reflection layer; and
a light-transmitting semiconductor layer disposed on the first reflection layer and having an upper light-extracting surface, wherein the first reflection layer is closer to the upper light-extracting surface than the second reflection layer, an interval between the upper light-extracting surface and the first reflection layer is equal to or smaller than 5 μm, wherein the upper light-extracting surface comprises a plurality of cone-shaped portions.
13. The light-emitting element of claim 12 , wherein an interval between the first and second reflection layers is equal to or smaller than 3 μm.
14. The light-emitting element of claim 12 , wherein a ratio of a maximum vertical length of the multi-layer light-emitting structure to an interval between the first and second reflection layers is equal to or greater than 0.9, and the ratio is smaller than 1.
15. The light-emitting element of claim 12 , wherein the second reflectance is greater than 95%, and the first reflectance ranges from 45% to 95%.
16. The light-emitting element of claim 12 , wherein the second reflection layer comprises a Bragg reflector.
17. The light-emitting element of claim 16 , wherein the first reflection layer comprises another Bragg reflector containing semiconductor material.
18. The light-emitting element of claim 12 , wherein the second reflection layer comprises a metal reflection mirror.
19. The light-emitting element of claim 18 , wherein the first reflection layer comprises a Bragg reflector containing semiconductor material.
20. The light-emitting element of claim 12 , further comprising a first conductive pad and a second conductive pad, wherein the multi-layer light-emitting structure comprises an n-type semiconductor layer, a p-type semiconductor layer, and an active layer disposed between the n-type semiconductor layer and the p-type semiconductor layer, and the first conductive pad is electrically connected to the n-type semiconductor layer, the second conductive pad is electrically connected to the p-type semiconductor layer, wherein the first conductive pad, the second conductive pad, and the second reflection layer are disposed on a same side of the first reflection layer.